Rebuilt how AI Studio knows what a model can do (#960)

app/MindWork AI Studio/Models/ImageLimits.cs

@@ -0,0 +1,55 @@
+namespace AIStudio.Models;
+
+/// <summary>
+/// How many images a model accepts, where anybody has said so.
+/// </summary>
+/// <remarks>
+/// Both numbers exist in the wild and they are not the same one: Anthropic documents a limit for a
+/// whole request, while vLLM limits each prompt through --limit-mm-per-prompt and ships with that
+/// set to one image. A model card may state either without the other, which is why each is optional
+/// on its own instead of sharing one "is known" flag.
+///
+/// Zero is a real answer here, not a stand-in for unknown: an operator can configure an engine to
+/// accept no images at all. Unknown is null.
+/// </remarks>
+/// <param name="MaxPerMessage">How many images fit into one message, or null when nobody has said.</param>
+/// <param name="MaxPerRequest">How many images fit into one request, or null when nobody has said.</param>
+public readonly record struct ImageLimits(int? MaxPerMessage, int? MaxPerRequest)
+{
+    /// <summary>
+    /// The number to show a user, or to plan with, where nothing is known.
+    /// </summary>
+    /// <remarks>
+    /// This is a number for whoever needs one, never a limit to enforce. Today, saying that a model
+    /// takes several images says nothing about how many, and turning that into a hidden ceiling of
+    /// six would take something away from the models which handle a hundred.
+    /// </remarks>
+    public const int DEFAULT_MAX_IMAGES = 6;
+
+    /// <summary>
+    /// The limits of a model nobody has written anything about.
+    /// </summary>
+    public static readonly ImageLimits UNKNOWN = new(null, null);
+
+    /// <summary>
+    /// Whether either of the two numbers is known.
+    /// </summary>
+    public bool IsKnown => this.MaxPerMessage.HasValue || this.MaxPerRequest.HasValue;
+
+    /// <summary>
+    /// How many images may travel in one message, as far as anybody has said.
+    /// </summary>
+    /// <remarks>
+    /// A message is part of a request, so a message cannot carry more than a whole request may --
+    /// whichever of the two numbers is smaller decides, and a number nobody stated does not decide
+    /// anything. Null means nobody stated either, which is a gap and never a limit of zero.
+    /// </remarks>
+    public int? MaxInOneMessage => (this.MaxPerMessage, this.MaxPerRequest) switch
+    {
+        ({ } perMessage, { } perRequest) => Math.Min(perMessage, perRequest),
+        ({ } perMessage, null) => perMessage,
+        (null, { } perRequest) => perRequest,
+
+        _ => null,
+    };
+}